Our current aim is to make more "green" industries by searching for ways to make better yields and

In the last decade, there has been growing interest in the use of microwave irradiation for organic synthesis. Microwave heating offers various advantages like controlled heating and cooling, shorter reaction times, and reduction of secondary products (Montes et al., 2006). In addition, microwave ovens offer a cheaper and cleaner alternative to oil baths present in many organic reactions. Also, microwave heating is more effective in solvent-free reactions and in those reactions, that do not use catalysts (Varma, 2010).

In this experiment, meso-stilbene dibromide was used to produce diphenylacetylene through two sequential dehydrohalogenations. The first part is a concerted E2 mechanism, where the reactant is deprotonated at the beta carbon from the halide ion that will be leaving. This creates a transition state where the leaving hydrogen and halide are anti-periplanar with each other, meaning that they are at a 180° angle in relation to one another. This reaction is caused by a base—in this case, potassium hydroxide—and produces a haloalkene, or vinyl halide. Potassium hydroxide was only added to reaction when needed, as

Furthermore, the principles and metrics of green chemistry were incorporated into the synthesis reaction through the use of the benign solvent, water. Through the use of the vacuum filtration and the recrystallization procedures, the product was further purified. Subsequently, the purity and identity of the product were evaluated through the analysis tool of Nuclear Magnetic Resonance. Ultimately, the efficiency and greenness of the reaction were measured through the calculation of the percent yield and the atom

The purpose of this experiment was to determine the relative reactivities of different types of hydrogen atoms toward bromine atoms. Although the tested compounds were all arenes, their reactivities differ as they contain different types of hydrogens. The hydrogens could be of three different types and could also differ in being bonded to carbons that are attached to a different number of other carbons. The three different types of hydrogens that could be found were aromatic, aliphatic, and benzylic. The first category is aromatic hydrogens, which are attached to sp2 carbons or are those directly bonded to an aromatic ring. Aromatic hydrogens are the least reactive of the hydrogens in this experiment. The second type of hydrogen being investigated is aliphatic hydrogens, which are found bonded to an SP3 hybridized carbon which are bonded to another SP3 hybridized carbon. Aliphatic hydrogens can also be broken down into further categories according to their number of substituents into primary (less reactive), secondary (more reactive), and tertiary (most reactive). The third type of hydrogens are benzylic hydrogens, which are bonded to a SP3 hybridized carbon that is bonded to a benzene ring. Benzylic hydrogens are also broken into primary and secondary categories according to their substituents, and are all more reactive than aliphatic and aromatic hydrogens.

tetraphenylcyclopentadienone- or TPCPD- as our diene, and our dieneophiles were three different alkenes with three different substituent groups (Kilway, “Formation”). The first reaction, synthesis of dimethyl tetraphenylphthalate, combined TPCPD and dimethyl acetylene-dicarboxylate using nitrobenzene as a solvent. Nitrobenzene makes a perfect solvent for this reaction because it’s boiling point is so high (210-211⁰C) (Kilway, “Formation”). This allows the reaction to reach the proper temperature to fulfill the activation energy needed to combine these two stable products without destroying the solvent (Drew-Gounev). If the solvent was destroyed, it may prevent the intended products from being produced. In this reaction, a strained

For this experiment, a dehydrobromination was performed on a meso-stilbene dibromide to form an alkyne. The meso-dibromostilbene was converted into diphenylacetylene, an alkyne, through two E2 elimination reactions. The dibromostilbene reacted with a strong base, potassium hydroxide, at a very high temperature. The hydroxide, from KOH, deprotonated one of the aliphatic hydrogen atoms or protons which formed an alkene and broke one of the C-Br bonds releasing the bromine. This process does not take much energy to remove one of the H-Br. This process was completed twice, and the second C-Br bond was broken, and an alkyne formed. This process was more difficult due to the rotation needed to perform the initial elimination. The elevated temperature

As UV and bromine were needed for the conversion reaction to occur, the mechanism must require light as an energy source and the chemical bromine to occur. The proposed mechanism begins with an initiation step of homolytic cleavage of bromine. When the UV light hit the bromine, highly reactive bromine free radicals formed. In the propagation steps, intermediates were formed; a free Br radical attacked the C=C double bond of dimethyl maleate, breaking the pi bond into a single bond, attaching Br to one of the Carbons, and giving a free radical to the other carbon from the destroyed double bond. Without the pi bond, the Carbons could rotate; one of the esters on the intermediate rotated 180°. Due to steric hindrance, the ester was likely to rotate

Grignard reaction mechanism, the bond between the carbon and magnesium attached tot eh carbon with the oxygen double bond. In the end the carbon is attached to three benzene

That is because there are not many chemistries can be done with Hydrogen which is not an extremely reactive functional group. The hydrogen is generally mentioned in terms of proton and acid-base chemistry. However, there actually is a reaction can be done with Hydrogen, a free radical substitution which is performed with halogen. The general reaction is like R-H +X2  R-H +HX,

Due to time constraints, we weren't able to get as much done as originally intended. Several reactions had to be completed multiple times and still had varying results. By the end, most of our products were not completely isolated but we did have evidence of some product formed for each. This lab gave us the opportunity to see reactions such as the Grignard reaction, bromination of a C=C bond, and the saponification of an ester. Additionally, we learned about the reactivity of acid chlorides and difficulties associated with them.

As a class, we were able to compare and contrast the colors of the aromatic azo compounds from several different coupling partners as well as different substitution patterns for each (i.e. ortho, para, meta). This type of synthesizing molecules to create an array of potentially useful compounds is known as combinational chemistry. In combinatorial synthesis, when using a compound with multiple points of diversity, or R groups which can be substituted, a substantial number of possible structures can be found depending on the number of substituents utilized. Laboratories can use automated technologies to perform these types of reactions on an industrial scale but scientists can also utilize these methods to synthesize and compare a select few molecules [2]. More specifically, the type of combinatorial synthesis utilized by our lab is known as “parallel synthesis”. In parallel synthesis, a number of reactants are available to react individually with a number of substrates which produces a substantial number of unique and potentially useful compounds. One way of organizing the information about these reactions is to create a table with the reactants

This lab consisted of the conversion of alcohols into alkyl halides through common substitution methods. These methods include SN1 and SN2 mechanism, both of which can occur for this type of reaction. For both reactions, the first step of protonation will be to add hydrogen to the –OH group and then the rest of the reaction will proceed according to the type of mechanism. SN1 reactions form a cation intermediate once the H2O group leaves, then allowing a halide (such as Br) to attack the positively charged reagent1. On the other hand, SN2 reactions are one-step mechanism in which no intermediate is formed and the halide attaches as the leaving

Organic Chemistry has always been a source of great fun and challenge to me. As a result of my earnest passion for the subject and outstanding record (third rank in the class out 93 students & first rank in the laboratory out 24 students), I was selected to participate as summer teaching assistant in organic chemistry, and received the honor to join Dr. Sunasee’s Research Lab. My time as summer teaching assistant enriched my academic experience in teaching and peer tutoring and also advanced my skills in chemistry.

Synthesis gas is a versatile intermediate feedstock for fuel and value added chemical synthesis. It is a mixture of hydrogen and carbon monoxide in various ratios. The composition of synthesis gas can be widely varied, depending on the synthesis processes and the composition of the raw materials, i.e. their hydrogen-to-carbon ratios and their reactivity’s. Synthesis gas can be produced not only from natural gas, petroleum, petroleum derivatives, or coals but also from almost any organic material, including biomass and organic wastes [1]. Synthesis gas have been synthesizing for many years in commercial level. There are number of stablished techniques used in industries to produce synthesis gas depending on the downstream requirements. Because of its adaptable nature synthesis gas has a variety of uses. The carbon monoxide in synthesis gas can all be converted to hydrogen via the water-gas shift reaction and again carbon monoxide in high purity can be obtained by low-temperature (cryogenic) separation or absorption in aqueous copper salt solutions.

This Chapter discusses the progress made using the Nottingham Pulse Rig towards determining the mechanism of the Fischer Tropsch reaction. A summary of the three main mechanisms proposed in the literature was outlined in Chapter 1 but is still the subject of much debate.1-6 Generally the carbide mechanism is accepted for Fe catalysts,7 but the mechanism over Co catalysts is less clear.1 Ge and Neurock,8 as well as Ojeda et al.,4 have suggested that the carbide mechanism is the pathway for FT synthesis on Co catalysts. However, they disagree over the route to CO dissociation; direct dissociation of the carbonyl bond has been proposed by Ge and Neurock, whilst Ojeda et al. have concluded that carbonyl dissociation proceeds via an H assisted